Xf.  recalcination temperature

ABSTRACT

SCRAP VULCANIZED RUBBER IS DISTRUCTIVELY DISTILLED TO PRODUCE A CHAR, AND THIS CHAR IS POST-CALCINED AT 1800* F. OR THEREABOUT, USUALLY UNTIL THE BENZENE-EXTRACTABLE CONTENT IS NO MORE THAN SUBSTANTIALLY 0.5 PERCENT OF THE WEIGHT OF THE CHAR. THE POST CALCINATION PREFERABLY IS CARRIED OUT IN A SMALLER VESSEL THAN THE DESTRUCTIVE DISTILLATION. THE STRESS-STRAIN PROPERTIES OF VULCANIZATE REINFORCED WITH THE   POST-CALCINED CHAR AND THE CURE RATE OF THE RUBBER ARE INCREASED.

DEFENSIVE PUBLICATION UNITED STATES PATENT AND TRADEMARK OFFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 10, 196 9, 869 0.G. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered scriesand are arranged chronologically. 'lhe heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent and Trademark Office makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED NOVEMBER 4, 1975 T940,011 POST-CALCINATION 0F VULCANIZED- RUBBER CHAR Grant Crane, Woodrow A. Wilson, and Edward L. Kay,

Akron, Ohio, assignors to The Firestone Tire & Rubber Company, Akron, Ohio Continuation of application Ser. No. 270,135, July 10,

1972, which is a continuation-in-part of application Ser. No. 235,982, Mar. 20, 1972, now abandoned. This application June 20, 1974, Ser. No. 481,008

Int. Cl. C09c 1/48 U.S. Cl. 423-449 2 Sheets Drawing. 11 Pages Specification SCRAP RUBBER DESTRUCTIVE DISTILLATION AT ABOUT I200 F. W A

LARGE CALCINER POST CALCINATION AT ABOUT lSOO F. IN A SMALL CALCINER FLUID-ENERGY MILL GRINDING SCRAP RUBBER DESTRUCTlVE DISTILLATION AT ABOUT I200 E IN A LARGE CALCINER FLUID-ENERGY MlLL GRINDING POST CALCINATION AT ABOUT |eoo F. IN A SMALL CALCINER Scrap vulcanized rubber is destructively distilled to produce a char, and this char is post-calcined at 1800 F. or thereabout, usually until the benzene-extractable content is no more than substantially 0.5 percent of the weight of the char. The post calcination preferably is carried out in a smaller vessel than the destructive distillation. The stress-strain properties of vulcanizate reinforced with the post-calcined char and the cure rate of the rubber are increased.

NOV. 4, 1975 G. CRANE et a1. T940,011

POST-CALCINATION OF VULCANIZED-RUBBER CHAR Original Filed June 20, 1974 Sheet 1 of 2 SCRAP RUBBER DESTRUCTIVE DISTILLATION G I AT ABOUT I200 F. IN A LARGE CALCINER POST CALCINATION AT ABOUT I800 F. IN A SMALL CALCINER FLUIDENERGY MILL GRINDING SCRAP RUBBER DESTRUCTIVE DISTILLATION AT ABOUT |2oo E IN A F162 LARGE CALCINER FLUID-ENERGY MILL GRINDING POST CALCINATION AT ABOUT I800 F. IN A SMALL CALCINER Nov. 4, 1975 G. CRANE et a1.

POST-CALCINATION OF VULCANIZED-RUBBER CHAR Original Filed June 20, 1974 Sheet 2 of 2 i4'oo I660 F. RECALCINATION TEMPERATURE FIC5.3 

